These days I’m pondering the question “What is neutral spine”? Thomas Hanna gave excellent answers in his book “Somatics: Reawakening The Mind’s Control Of Movement, Flexibility, And Health”. He proposed 2 Feldenkrais Awareness Through Movement lessons to reverse the effects of aging and to find back to a spine that is not too much flexed in any direction. Thomas Hanna uses slightly different terms than Dr. Moshe Feldenkrais, but basically he is talking about the same things.
Btw, in his book Thomas Hanna describes the 2 lessons rather briefly. In “My Feldenkrais Book” you will find the same 2 lessons, but in an extended version, and with beautiful photographs instead of black-and-white photographs of wooden puppets. Lesson 5: Cleaning up crunches, and Lesson 6: Lifting the head.
Now I was googling for pictures of neutral spine and couldn’t find anything meaningful. I found the well know postural types illustration, which is highly not satisfactory. Instead of investing a day to paint my own, I just quickly made some annotations:
I drew 3 sections, using yellow, green, and blue: cervical spine, thoracic spine, lumbar spine. And also a lowermost one for the pelvis. So it’s 4 in total. With these 4 sections is easier to see what’s going on.
I made annotations: 0 for neutral, + and ++ for too much, - and - - for too little flexion.
You will find that using my quickly put together annotation “system” you will be able to draw 30 or more postures, not just 4. I figure the original illustration is pretty much arbitrary and not as complete as people would love to think.
I also whitened the dotted lines, and replaced them with black ones going from C1 through the hip joint. In this way now you can see if the person is leaning forward (and how much). The illustrations lack a leaning backward posture.
Looking at these postures, I would predict that B will suffer from lower back pain (due to overly contracting the lumbar flexor muscles), C will suffer from lower back pain (due to habitual flexion AND loading of the lumbar spine), and D will completely ruin his/her feet (starting with Hallux Valgus).
Now, this is all fun drawings and eye candy. The real challenge begins when you want to FEEL what neutral feels like. Instead of embarking into a 10 years Odyssey, I recommend taking Feldenkrais lessons for that.